Simple titrimetric method for the analytical control of macromolecular polypeptides

Area of Science:

• Biochemistry
• Analytical Chemistry
• Protein Chemistry

Background:

• Polypeptide degradation affects protein function and stability.
• Accurate detection of peptide bond hydrolysis and deamination is crucial for quality control and research.
• Existing methods may lack simplicity or specificity for certain decomposition processes.

Purpose of the Study:

• To present a simple potentiometric procedure for determining primary amino groups in polypeptides.
• To assess the method's suitability for detecting peptide chain splitting and deamination.
• To apply the developed method to analyze specific biologically relevant peptide fragments.

Main Methods:

• Potentiometric determination of primary amino groups.
• Analysis of macromolecular polypeptides.
• Application to corticotropin fragments (ACTH(1-28), ACTH(1-32)), Angiotensin II, and Kunitz base (Trasylol).

Main Results:

• The potentiometric method successfully quantifies primary amino groups in polypeptides.
• The procedure is suitable for identifying decomposition involving peptide bond cleavage and deamination.
• The method was validated using various peptide samples, demonstrating its applicability.

Conclusions:

• A straightforward potentiometric assay for primary amino groups offers a reliable tool for polypeptide analysis.
• This method can effectively monitor degradation pathways in protein samples.
• The technique is applicable to diverse peptide structures, including hormones and enzyme inhibitors.